Duct Mastic

Duct leakage is a major problem with forced-air heating or air-conditioning systems. When ducts are run outside of the conditioned spaceInsulated, air-sealed part of a building that is actively heated and/or cooled for occupant comfort.
, heating and cooling efficiencies may be cut in half due to leakage. Tightly sealed ducting is extremely important in ensuring high energy efficiency of forced-air HVAC(Heating, ventilation, and air conditioning). Collectively, the mechanical systems that heat, ventilate, and cool a building. equipment.

Experts strongly recommend flexible duct mastics—not duct tape—for sealing ducts, as mastics last longer under high temperatures. In some applications, however, the messiness of mastics can be a problem. Newer types of duct tape, such as oriented polypropylene or butyl tapes, can outlast standard cloth duct tape, but joints must still be mechanically fastened. GreenSpec lists sealants with a maximum VOCVolatile organic compound. An organic compound that evaporates readily into the atmosphere; as defined by the U.S.
Environmental Protection Agency, VOCs are organic compounds that volatize and then become involved in photochemical smog production. content of 50 g/L.

Duct leakage is a major problem with forced-air heating or air-conditioning systems. When ducts are run outside of the conditioned space, heating and cooling efficiencies may be cut in half due to leakage. Tightly sealed ducting is extremely important in ensuring high energy efficiency of forced-air HVAC equipment.
Experts strongly recommend flexible duct mastics—not duct tape—for sealing ducts, as mastics last longer under high temperatures. In some applications, however, the messiness of mastics can be a problem.